Co-expression of CD39 and CD103 identifies tumor-reactive CD8 T cells in human solid tumors.

Identifying tumor antigen-specific T cells from cancer patients has important implications for immunotherapy diagnostics and therapeutics. Here, we show that CD103+CD39+ tumor-infiltrating CD8 T cells (CD8 TIL) are enriched for tumor-reactive cells both in primary and metastatic tumors. This CD8 TIL subset is found across six different malignancies and displays an exhausted tissue-resident memory phenotype. CD103+CD39+ CD8 TILs have a distinct T-cell receptor (TCR) repertoire, with T-cell clones expanded in the tumor but present at low frequencies in the periphery. CD103+CD39+ CD8 TILs also efficiently kill autologous tumor cells in a MHC-class I-dependent manner. Finally, higher frequencies of CD103+CD39+ CD8 TILs in patients with head and neck cancer are associated with better overall survival. Our data thus describe an approach for detecting tumor-reactive CD8 TILs that will help define mechanisms of existing immunotherapy treatments, and may lead to future adoptive T-cell cancer therapies

997 T cell immunotherapies trigger neutrophils to eliminates heterogenous tumors

Background Immune surveillance can eliminate developing cancers at the early stages of malignant transformation. The selective pressure that the immune system imposes on tumor cells, however, can “edit” tumors, yielding immune escape variants. Many tumors contain clones that cease to express antigenic proteins. Intra-tumoral antigenic heterogeneity is an important mechanism by which progressing tumors become refractory to standard immunotherapeutic interventions. This is particularly problematic for interventions that target a single antigen, such as adoptive T cell therapies and CAR T cells. Current immunotherapies in the clinic consist of strategies that mobilize the adaptive compartment of the immune system. The most common approaches include immune checkpoint blockade with antibodies, infusion of ex vivo educated or genetically modified tumor-specific T cells, and therapeutic anti-tumor vaccination. Moreover, a wave of agents that target tumor necrosis factor receptor (TNFR) superfamily members expressed by activated T cells, such as glucocorticoid induced TNF receptor (GITR), 4-1BB and OX40 are being further investigated. The role of neutrophils in tumor promotion versus tumor elimination is not well understood. The pro-tumorigenic role of neutrophils in chronic inflammation has been described. Higher neutrophil-to-lymphocyte ratios are associated with deleterious outcomes in patients receiving immune checkpoint blockade. Moreover, neutrophil effector mechanisms such as the formation of NETs can promote metastases and can shield tumors from effector T cell elimination. In other models, however, neutrophils and NETs can directly kill cancer. The role of neutrophils as potential effectors in the context of immunotherapies that target T cells remains incompletely defined. Methods We applied a combination therapy consisting of cyclophosphamide (CTX), CD4+ T cells specific for the melanoma antigen Trp1 (Trp1 cells), and an anti-OX40 agonist or anti-CTLA-4 antagonist antibodies to mice bearing advanced antigenically heterogeneous melanomas. Results Complete eradication of heterogenous melanomas was observed in mice treated with the combination therapy. Surprisingly, regressing tumors were heavily infiltrated with neutrophils with a distinct anti-tumorigenic phenotype and neutrophil depletion abrogated tumor eradication. Upon closer examination, we observed that inducible nitric oxide synthase expressed by neutrophils was necessary for heterogenous tumor elimination. In support of these findings, extensive neutrophil activation in biopsies of melanoma patients treated with immune checkpoint blockade. Moreover, our findings uncover a novel interplay between T cells mediating the initial anti-tumor immune response, and neutrophils mediating the destruction of tumor antigen loss variants

PD-1 and ICOS co-expression identifies tumor-reactive CD4 T cells in human solid tumors.

CD4 T helper (Th) cells play a key role in orchestrating immune responses, but the identity of the CD4 Th cells involved in the anti-tumor immune response remains to be defined. We analyzed the immune cell infiltrates of head and neck squamous cell carcinoma and colorectal cancers and identified a subset of CD4 Th cells distinct from FOXP3+ regulatory T cells that co-express PD-1 and ICOS. These tumor-infiltrating CD4 Th cells (CD4 Th TIL) have a tissue-resident memory phenotype, are present in MHC class II-rich areas and proliferate in the tumor suggesting local antigen recognition. The T-cell receptor repertoire of the PD-1+ICOS+ CD4 Th TIL is oligoclonal, with T-cell clones expanded in the tumor, but present at low frequencies in the periphery. Finally, these PD-1+ICOS+ CD4 Th TIL were shown to recognize both tumor-associated antigens and tumor-specific neoantigens. Our findings provide an approach for isolating tumor-reactive CD4 Th TIL directly ex vivo that will help define their role in the anti-tumor immune response and potentially improve future adoptive T-cell therapy approaches

Tumor resident memory CD8 T cells and concomitant tumor immunity develop independently of CD4 help.

Tissue resident memory (Trm) CD8 T cells infiltrating tumors represent an enriched population of tumor antigen-specific T cells, and their presence is associated with improved outcomes in patients. Using genetically engineered mouse pancreatic tumor models we demonstrate that tumor implantation generates a Trm niche that is dependent on direct antigen presentation by cancer cells. However, we observe that initial CCR7-mediated localization of CD8 T cells to tumor draining lymph nodes is required to subsequently generate CD103+ CD8 T cells in tumors. We observe that the formation of CD103+ CD8 T cells in tumors is dependent on CD40L but independent of CD4 T cells, and using mixed chimeras we show that CD8 T cells can provide their own CD40L to permit CD103+ CD8 T cell differentiation. Finally, we show that CD40L is required to provide systemic protection against secondary tumors. These data suggest that CD103+ CD8 T cell formation in tumors can occur independent of the two-factor authentication provided by CD4 T cells and highlight CD103+ CD8 T cells as a distinct differentiation decision from CD4-dependent central memory